Weed Hosts of Root-Knot Nematodes and Their Distribution in Fiji

Weeds can act as reservoir hosts of a range of pests and diseases. Information and knowledge on the host status of weeds to common pests and diseases can be used to develop integrated weed and pest management strategies. As part of a survey on the distribution and diversity of root-knot nematodes on crops in Fiji, the root-knot nematode host status of weeds was also studied. Weeds growing in root-knot nematode infested farms (n= 189) and bioassay pot soil samples (n= 277) were identified, and their host status was determined on the basis of a root gall and egg-mass index scale from 0 to 5. A total of 45 weed species were recorded as potential weed hosts of root-knot nematodes with a gall index from 1 to 5. Using the weed and tomato bioassay method, a total of 11 nonhost weed species were recorded with a gall index of 0, relative to infected tomato growing in pot soil samples. Common weeds infected by root-knot nematodes on farms and in bioassay pot soil included slender amaranth, old world diamond-flower, tropic ageratum, sicklepod, mimbra, balsamapple, purple bushbean, little ironweed, ivy gourd, and cutleaf groundcherry. The presence of egg masses on the weed hosts indicated their ability to sustain root-knot nematode populations and, thus, their potential to act as reservoir hosts.

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Survey and Identification of Root-Knot Nematodes Associated with Brinjal Crops in Fatehabad, Agra

Current Agriculture Research Journal ◽

10.12944/carj.4.1.13 ◽

2016 ◽

Vol 4 (1) ◽

pp. 114-119

Author(s):

Bindhya Yadav ◽

Sanoj Kumar

Keyword(s):

Meloidogyne Javanica ◽

Mixed Population ◽

Egg Mass ◽

Root Knot Nematode ◽

Index Point ◽

Root Knot Nematodes ◽

Heavy Infection ◽

Disease Occurrence ◽

Gall Index ◽

Almost All

A survey was conducted over a period of one and half year to estimate the occurrence of root-knot nematode disease on brinjal crops in five selected localities in and around Fatehabad, Agra. Our survey indicates that brinjal crops grown in the selected localities were heavily infested with root-knot nematodes. Highest frequency of disease occurrence in which almost all the roots have knot-like appearance (>85%) was reported from Firozabad Road area. Other localities were also having the significant infestations and these were reported as 80%, 78%, 65%,62% respectively. To access the damage caused by root-knot nematodes in brinjal crop, Meloidogyne gall index and its egg-mass index were calculated and these were found in the range of 2-5. An increased gall index and egg-mass index point to heavy infection on selected crops. Sampled crop showed the significant presence of Meloidogyne javanica. However, there were other species of root-knot nematode as mixed population was also reported. Other species of the root-knot nematodes which were reported in this survey was M. incognita. This survey indicates that the M. javanica is a frequently occurring population in brinjal field infested with root-knot disease.

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Susceptibility of Eight Herbs to Common Root-Knot Nematodes

Journal of Environmental Horticulture ◽

10.24266/0738-2898-20.2.101 ◽

2002 ◽

Vol 20 (2) ◽

pp. 101-103

Author(s):

Jerry T. Walker

Keyword(s):

Meloidogyne Incognita ◽

Mass Production ◽

Root Systems ◽

Common Species ◽

Egg Mass ◽

Common Root ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Gall Index ◽

Herb Species

Abstract Eight herb species were inoculated with two common species of root-knot nematode and grown for 2 months in a greenhouse. Root systems were examined for galls and egg mass production. All herb species were susceptible but developed fewer galls and had lower gall indices than Rutgers tomato. Burnet, chives, valerian and winter savory had few galls or low gall indices. Eggs were produced on all. Chamomile had a high gall index. Chicory, parsley, and sorrel had intermediate indices. Herbs were equally susceptible to the southern (Meloidogyne incognita) and peanut root-knot nematodes (M. arenaria), particularly at the highest inoculum densities. Mean dry weights of inoculated herbs were not always significantly less than the non-inoculated plants, suggesting that some herbs may be tolerant to root-knot nematodes.

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Weed Hosts of Root-Knot Nematodes in Tomato Fields

Journal of Plant Protection Research ◽

10.2478/v10045-012-0036-1 ◽

2012 ◽

Vol 52 (2) ◽

pp. 230-234 ◽

Cited By ~ 6

Author(s):

Fatemeh Gharabadiyan ◽

Salar Jamali ◽

Amir Yazdi ◽

Mohammad Hadizadeh ◽

Ali Eskandari

Keyword(s):

Cyperus Rotundus ◽

Parasitic Nematodes ◽

Egg Mass ◽

Natural Ecosystem ◽

Weed Species ◽

New Host ◽

Root Knot Nematodes ◽

Field Crops ◽

Lactuca Serriola ◽

Weed Hosts

Weed Hosts of Root-Knot Nematodes in Tomato Fields Root-knot nematodes (Meloidogyne spp.) are one of the three most economically damaging genera of plant parasitic nematodes on horticultural and field crops. Root-knot nematodes are distributed worldwide, and are obligate parasites of the roots of thousands of plant species. All major field crops, vegetable crops, turf, ornamentals, legumes and weeds are susceptible to one or more of the root-knot species. In this study, nineteen weed species were found to be hosts for Meloidogyne incognita, M. javanica, M. arenaria race 2, and M. hapla in tomato fields in Khorasan Province, Iran. Egg mass production and galling differed (p < 0.05) among these weed species: Amaranthus blitoides, Portulaca oleracea, Polygonum aviculare, Convolvulus arvensis, Cyperus rotundus, Plantago lanceolatum, Rumex acetosa, Solanum nigrum, Datura stramonium, Acroptilon repens, Alcea rosa, Alhaji camelorum, Chenopodium album, Echinochla crusgalli, Hibiscus trionum, Kochia scoparia, Malva rotundifolia, Setaria viridis, Lactuca serriola. The species P. oleracea, A. blioides, S. nigrum, P. lanceolatum, Ch. album, and C. arvensis are major threats to the natural ecosystem in the Iranian province of Khorasan. A. blitoides collected from tomato fields was a good host for 4 Meloidogyne species. C. arvensis, as an important weed, was a distinguished appropriate host for M. hapla, M. incognita, M. javanica. S. nigrum and Ch. album were good hosts for M. hapla, M. javanica, M. incognita race 1, and M. arenaria race 3. In this survey, we reported E. crusgalli as a new host of M. javanica and C. rotundus was a good host for M. arenaria and M. incognita. S. nigrum was also reported as a new host of M. hapla. R. acetosella was reported as a host of M. arenaria. M. incognita was recently described as a new species infecting D. stramonium worldwide.

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Reproduction of Meloidogyne enterolobii in lettuce cultivars of the American group

Horticultura Brasileira ◽

10.1590/s0102-053620150000200002 ◽

2015 ◽

Vol 33 (2) ◽

pp. 147-150

Author(s):

Érika CSS Correia ◽

Norberto Silva ◽

Marylia GS Costa ◽

Silvia RS Wilcken

Keyword(s):

Reproductive Potential ◽

Egg Mass ◽

Root Knot Nematodes ◽

Second Stage ◽

American Group ◽

Meloidogyne Enterolobii ◽

Meloidogyne Spp ◽

Gall Index ◽

Summer Time ◽

Reproduction Factor

Lettuce is the main vegetable cultivated in Brazil, in volume and in marketed value. There are ranges of diseases which may affect lettuce crops, including those caused by root-knot nematodes (Meloidogyne spp.). We evaluated the reproductive potential of Meloidogyne enterolobii in 22 lettuce cultivars. The plants were inoculated with 5,000 eggs and eventuals second stage juveniles of nematode per pot, two days after the transplanting. 'Rutgers' tomato was used as standard for inoculum viability of M. enterolobii. We evaluated, 60 days after inoculation, the gall index, egg mass index and reproduction factor (RF). The 'Ithaca', 'Raider Plus', 'RS-1397', 'L-104', 'Challenge', 'IP-11', 'Classic', 'Salinas 88', 'Vanguard 75', 'Calona' and 'Desert Queen' were resistant to M. enterolobii with RF varying from 0.22 to 0.9, and the cultivars Lady Winterset, Robinson, Sonoma, Raider, Lucy Brown, Bnondaga, Summer Time, Taina, Sundevil and L-109 were susceptible to this nematode, with RF ranging from 1.06 to 5.73.

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HOST STATUS OF INDIGENOUS LEAFY VEGETABLE AND WEED SPECIES TO ROOT-KNOT NEMATODES

Acta Horticulturae ◽

10.17660/actahortic.2013.1007.47 ◽

2013 ◽

pp. 417-425 ◽

Cited By ~ 1

Author(s):

N. Ntidi ◽

W.S. Jansen van Rensburg ◽

D. Fourie ◽

A. McDonald

Keyword(s):

Leafy Vegetable ◽

Weed Species ◽

Root Knot Nematodes ◽

Host Status

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A New Expanded Host Range of Cucurbit yellow stunting disorder virus Includes Three Agricultural Crops

Plant Disease ◽

10.1094/pdis-93-7-0685 ◽

2009 ◽

Vol 93 (7) ◽

pp. 685-690 ◽

Cited By ~ 32

Author(s):

William M. Wintermantel ◽

Laura L. Hladky ◽

Arturo A. Cortez ◽

Eric T. Natwick

Keyword(s):

Host Range ◽

Weed Species ◽

Specific Primers ◽

Snap Bean ◽

Buffalo Gourd ◽

Weed Hosts ◽

Potential Reservoir ◽

Limited Host Range ◽

Polymerase Chain ◽

Reservoir Hosts

Cucurbit yellow stunting disorder virus (CYSDV) was identified in the fall of 2006 affecting cucurbit production in the southwestern United States (California, Arizona), as well as in nearby Sonora, Mexico, resulting in nearly universal infection of fall melon crops in 2006 and 2007, and late infection of 2007 spring melons. Survival of CYSDV through the largely cucurbit-free winter months suggested the presence of weed or alternate crop hosts, although previous studies indicated a limited host range restricted to members of the Cucurbitaceae. To determine potential reservoir hosts for CYSDV in desert production, weed and crop hosts were collected from throughout the region over a period of 26 months, and were tested for the presence of CYSDV by reverse transcription–polymerase chain reaction (RT-PCR) using CYSDV HSP70h- and coat protein gene–specific primers. Many noncucurbits collected from infected melon fields and nearby areas were symptomless and virus free; however, CYSDV was detected in alfalfa (Medicago sativa), lettuce (Lactuca sativa), and snap bean (Phaseolus vulgaris), as well as in several weed species widely prevalent in the region. Typical crinivirus symptoms of interveinal yellowing and leaf brittleness were observed on CYSDV-infected snap bean, alkali mallow (Sida hederacea) and Wright's groundcherry (Physalis wrightii), while other infected crop and weed hosts were symptomless. Transmission tests demonstrated that lettuce, snap bean, alkali mallow, Wright's groundcherry, and buffalo gourd (Cucurbita foetidissima) could serve as virus reservoir hosts for transmission of CYSDV to melon and other cucurbits. These results expand the previously known host range of CYSDV, demonstrating that the virus is capable of infecting not only members of the Cucurbitaceae, but also plants in seven additional taxonomic families.

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Host Status of Lisianthus `Mariachi Lime Green' for Three Species of Root-knot Nematodes

HortScience ◽

10.21273/hortsci.39.1.120 ◽

2004 ◽

Vol 39 (1) ◽

pp. 120-123 ◽

Cited By ~ 3

Author(s):

Martin Schochow ◽

Steven A. Tjosvold ◽

Antoon T. Ploeg

Keyword(s):

Nematode Species ◽

Meloidogyne Hapla ◽

Cut Flower ◽

Root Knot Nematode ◽

Eustoma Grandiflorum ◽

Root Knot Nematodes ◽

Tomato Plants ◽

Flower Production ◽

Significant Damage ◽

Host Status

Lisianthus [Eustoma grandiflorum (Raf.) Shinn.] plants were grown in soil infested with increasing densities of Meloidogyne hapla Chitwood, M. incognita (Kofoid & White) Chitwood, or M. javanica (Treub) Chitwood, root-knot nematodes. Compared to tomato plants grown in soil with the same nematode numbers and species, lisianthus had less severe root symptoms, suffered less damage, and resulted in lower nematode multiplication rates. Lisianthus was a better host for M. javanica than for M. incognita, and a poor host for M. hapla. Lisianthus shoot weights were significantly reduced after inoculation with M. javanica or M. hapla, but not after M. incognita inoculation. The number of flowers produced per lisianthus plant was reduced by all three nematode species. The results show that the root-knot nematode species that are most common in California may cause significant damage in the cut-flower production of lisianthus.

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Resistance sources to root-knot nematodes Meloidogyne javanica, M. incognita and M. enterolobii in sweet potato

Horticultura Brasileira ◽

10.1590/s0102-053620200203 ◽

2020 ◽

Vol 38 (2) ◽

pp. 126-133

Author(s):

Paula Andrea O Carmona ◽

Jadir B Pinheiro ◽

Geovani Bernardo Amaro ◽

Giovani Olegario da Silva ◽

José Ricardo Peixoto ◽

...

Keyword(s):

Sweet Potato ◽

Population Increase ◽

Egg Mass ◽

Breeding Programs ◽

Root Knot Nematodes ◽

Nematode Reproduction ◽

Randomized Design ◽

Race 1 ◽

Gall Index ◽

Reproduction Factor

ABSTRACT One of the main obstacles for food production in many developing countries, as in Brazil, is the damage caused by root-knot nematodes, mainly those belonging to the genus Meloidogyne. This study aimed to assess the resistance levels of 44 sweet potato genotypes to M. javanica, M. incognita race 1 and M. enterolobii. These researches were carried out in 2014, under greenhouse conditions in Brasília-DF, Brazil. A completely randomized design with six replicates of one plant/plot/treatment was used. We determined the gall index (GI) and egg mass index (EMI) in the root system of each plant, the number of eggs and juveniles per gram of root with galls and the nematode reproduction factor. M. javanica was less aggressive and reproduced in only 9.09% of the evaluated genotypes; M. incognita race 1 was intermediate (47.73%); whereas M. enterolobii was more aggressive, with a population increase in 79.55% of the genotypes. The genotypes CNPH 1200, CNPH 1219, CNPH 1292, CNPH 1392, CNPH 60 and ‘Coquinho’ were the most resistant to the three species and can be used in breeding programs for multiple resistance to root-knot nematodes.

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Reaction of weeds, found in vegetable production areas, to root-knot nematodes Meloidogyne incognita and M. enterolobii

Horticultura Brasileira ◽

10.1590/s0102-053620190413 ◽

2019 ◽

Vol 37 (4) ◽

pp. 445-450

Author(s):

Jadir B Pinheiro ◽

Giovani Olegario da Silva ◽

Danielle Biscaia ◽

Amanda G Macedo ◽

Núbia Maria Correia

Keyword(s):

Meloidogyne Incognita ◽

Great Majority ◽

Egg Mass ◽

Vegetable Production ◽

Vegetable Crops ◽

Weed Species ◽

Root Knot Nematodes ◽

Hyptis Suaveolens ◽

Race 1 ◽

Production Areas

ABSTRACT Root-knot nematodes cause great damage to vegetable crops in Brazil, besides having a large range of host plants, such as weeds. Weeds can maintain the inoculums or even favor the multiplication of these nematodes. In this study we evaluated the reaction of selected weed species, present in a vegetable production area, to root-knot nematodes Meloidogyne incognita and M. enterolobii. The trials were conducted in a greenhouse at Embrapa Hortaliças, Brasília-DF, in a completely randomized design with six replicates. Fifteen weed species were evaluated for M. incognita race 1, and 16 weed species were evaluated for M. enterolobii. Two tomato cultivars were evaluated as resistance and susceptibility standards. Gall index (IG), egg mass index (IMO), number of eggs per gram of roots (eggs/g roots) and reproduction factor (FR) were evaluated. M. enterolobii survives and multiplies more easily in weeds collected in vegetable production areas than M. incognita race 1 and, the great majority of weed species evaluated in this study are hosts of both nematode species. Only the species Urena lobata, Sonchus oleraceus, Euphorbia heterophylla, Melampodium perfoliatum and Tagetes sp. were immune to M. incognita race 1. All evaluated species are either hosts or favor the multiplication of M. enterolobii. The species which are the most susceptible to M. incognita race 1, and therefore require greater control of crops infected by this nematode are Ipomoea nil, I. triloba and Eleusine indica, and for M. enterolobii are I. nil, Solanum americanum, Hyptis suaveolens, Portulaca oleracea, I. triloba and Euphorbia heterophylla.

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Host Reactions of Sweetpotato Genotypes to Root-knot Nematodes and Variation in Virulence of Meloidogyne incognita Populations

HortScience ◽

10.21273/hortsci.37.7.1112 ◽

2002 ◽

Vol 37 (7) ◽

pp. 1112-1116 ◽

Cited By ~ 18

Author(s):

J.C. Cervantes-Flores ◽

G.C. Yencho ◽

E.L. Davis

Keyword(s):

North Carolina ◽

Ipomoea Batatas ◽

Nematode Species ◽

Host Race ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Differential Reaction ◽

Geographical Regions ◽

Host Status ◽

Soil Mix

Sweetpotato [Ipomoea batatas (L.) Lam.] genotypes were evaluated for resistance to North Carolina root-knot nematode populations: Meloidogyne arenaria (Neal) Chitwood races 1 and 2; M. incognita (Kofoid & White) Chitwood races 1, 2, 3, and 4; and M. javanica (Treub) Chitwood. Resistance screening was conducted using 150-cm3 Conetainers containing 3 sand: 1 soil mix. Nematode infection and reproduction were assessed as the number of egg masses produced by root-knot nematodes per root system. Host suitability for the root-knot nematode populations differed among the 27 sweetpotato genotypes studied. Five genotypes (`Beauregard', L86-33, PDM P6, `Porto Rico', and `Pelican Processor') were selected for further study based on their differential reaction to the different root-knot nematodes tested. Two African landraces (`Tanzania' and `Wagabolige') were also selected because they were resistant to all the nematode species tested. The host status was tested against the four original M. incognita races, and an additional eight populations belonging to four host races, but collected from different geographical regions. The virulence of root-knot nematode populations of the same host race varied among and within sweetpotato genotypes. `Beauregard', L86-33, and PDM P6 were hosts for all 12 M. incognita populations, but differences in the aggressiveness of the isolates were observed. `Porto Rico' and `Pelican Processor' had different reactions to the M. incognita populations, regardless of the host race. Several clones showed resistance to all M. incognita populations tested. These responses suggest that different genes could be involved in the resistance of sweetpotato to root-knot nematodes. The results also suggest that testing Meloidogyne populations against several different sweetpotato hosts may be useful in determining the pathotypes affecting sweetpotato.

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